What devious game of three-dimensional political chess is she playing?

What Machiavellian strategy is behind her unexpected decision not to throw her hat in the ring?

Does she know something we don’t know about her prospects?

The chatterers and cynics were asking these questions in the wake of Madigan’s surprise announcement Friday that she won’t seek re-election next year, just as we were asking them eight years ago in the wake of Madigan’s surprise announcement that she wouldn’t be running for the U.S. Senate or governor in 2010.

Rumors are rampant:

• She’s secretly setting herself up to run for mayor of Chicago in two years!

• She’d rather let someone else deal with the state’s fiscal mess for the next four years, then she’ll run for governor!

• She’s lined up an appointment to another powerful job!

In the summer of 2009, the rumored appointment was to the Cabinet of her former seatmate in the Illinois legislature, President Barack Obama.

This year, the speculators and wild-guessers say she’s looking for a seat on the Illinois Supreme Court.

But Madigan never ran for mayor, governor or the U.S. Senate, and never got that Cabinet appointment.

And in a phone call Friday to the Tribune Editorial Board she denied having an interest in becoming a state Supreme Court justice, saying “Be a judge? That’s not me. They sit. I can’t sit all day.”

Last week, as in 2009, Madigan didn’t rule out a run for higher office at some point — “I’m ready for a new challenge,” was her vague explanation to the Editorial Board. In 2009, she said: “I have a job that I love right now,” adding that the decision not to seek a promotion was “agonizing” — which conventional wisdom saw as leaving the door open more than a crack.

Maybe, however — and I know how crazy this sounds but stay with me — maybe she’s not sufficiently consumed with ambition to devote the rest of her life to the pursuit of political advancement.

Maybe most of us were wrong in 2002, when she first ran for Illinois attorney general, to assume that she was as obsessed with yanking the levers of power as her father, veteran Democratic House Speaker Michael Madigan, and to assume that, like so many who occupy lower constitutional offices, she would reach for the next rung of the ladder as soon as she could.

Maybe the idea of subjecting herself to the brutal indignities of running for Illinois governor or mayor of Chicago, then becoming ringmaster of the circus that is Illinois or Chicago doesn’t appeal to her.

Maybe Friday’s announcement that she’ll step down as attorney general at the end of her current term in early 2019 was simply a move toward reinvention.

Maybe she changed her mind after having said in May that it was “the plan” for her to run for re-election. And maybe, at 51, she sees a better life for herself outside of electoral politics, a life in which she can earn a lot more money and undergo a lot less public scrutiny than she does now.

Maybe the reason she’s passed on many opportunities to seek advancement — including a run for governor in 2014 that looked certain until she bowed out — and now plans to leave politics, is that, at heart, she’s more of a normal person than we, and perhaps she, once thought.

Or maybe not.

My track record in making assumptions about Lisa Madigan has been poor. From initially discounting her appeal to voters and her talents, to overestimating the influence her father would have on her performance in office, to forecasting her next moves over the years, I’ve been as wrong as most of the other would-be analysts.

Lisa Madigan could be playing a long game here or have some dark reasons for her stunning about-face. I wanted to ask her about my theory and others, but her press office declined to arrange for a quick interview.

I can’t read her mind, but I can read her history from the past 16 years. It’s telling me I’m right this time. Maybe.